Engine Questions.
Turbo Mini Forums

Hey guys right question time.

I'm rebuilding my 998 bores are fine just need new set of rings (I've had it honed) I want to put a 1275 head on it, lightened fly wheel, Diff cam (Mg Metro sort of spec). duplex timing, Modded water and Oil ways already.

1. Will I need to deck it to higher the CR?
2. What oil pump should I use?
3. Centre oil pick up worth doing?
4. More breathers? since 998 has just one at back of the block?

anything else you wanna tell me would be helpful please

Thanks
Stephen

do you know what the chamber sizes are in the head now?

I need to get a cylinder head to be honest my mate had my old one off me but it should be standard 940 size

Central oil pick up is definitely worth doing.

You dont want to learn that one the hard way...

http://www.turbominis.co.uk/forums/index.p...tid=469104&fr=0

Std oil pump will be fine. If its in gd nick obviously

13.95 1/4 mile on a 2.95 fd. Carnt be that hard to beat!

if its of help, I ran a 1100 with a 295 head and MG cam, 3.7 diff on 10's; cracking engine for what it was (thrown together!). I used the standard pump (suited the cam i was using).

no idea what compression i was running; I just bolted it all together

Centre oil pick-up i'd certainly install.

Id buy a new pump binned my old one

and I'll be running 10's on 3.44 diff and 295 heads are hard to come by :( My mate has a New Old Stock BMC boxed 295 with no valves :/ he wont sell it though.

The 940 chambers {21.4cc nominal} are smaller than the 998 head chambers {24.5cc nominal} so fitting the 940 will raise the compression if the chambers are standard.

WWW.TURBO-MINI.COM

So no need for a head skim or block skim?

Thanks :)

What cc would the pockets be roughly for the valves?

Roughly 1cc iirc.

WWW.TURBO-MINI.COM

This how to create the pockets... if you are brave...

http://www.youtube.com/watch?feature=playe...A&v=jhurEimm16Y

I have a tech drawing for doing the pockets so coud use a milling machine.

That dudes being a hero much! I could do it that way but then again rather not...

I think that is our very own Robert in the video

it is

Did ir work though?

I'm sure there are a few that have cut the pockets this way

Ohh right Hmm could just send it to my old work though to have it done :)

whats sw5 came like?

If something is worth doing, it's worth doing half of.

i cut my pockets that way too, but i sleeved over the drill with a pvc pipe so the cutter only came out of the pipe the depth of the cut. this meant i could lean heavy on the pipe so it would cut and not jump up and wander across the block face. not ideal certainly, but worked a blooming treat :)

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Ohh why is everyone being hero's when doing this mod haha thanks :) may look into doing it

i did it by hand with an air die grinder and burrs. I would deck the block to at least clean the surface up if your going to use the 12g940 head as on my small bore there was a water way that pitted the block slightly but this is where cylinder 2 and 3 fire rings seal. personally i like to bring the pistons level with the block to narrow down the squish band but this is one of those subjects that people seem to differ on.

My small bore turbo project http://www.turbominis.co.uk/forums/index.php?p=vt&tid=473901

hi stephen ,

thanks for the pm , basically take it very slow and steady ,the main worry is the die grinder skating off across the deck,digging out divots of metal ,you could tape a old head gasket on there to protect it .
using a carbide cutter in a high power die grinder seemed to work well ,cutting side ways into the bore , to avoid going too deep ,you can put a piece of ally tape around the bore at the depth you want to cut and use this as a guage to keep you level and at the right depth .

good luck
robert

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM